1. Field of the Disclosure
The present disclosure generally relates to the field of auto-laundry systems of the type employing an endless loop chain conveyor linking a plurality of car-pusher dollies that roll along slotted tracks, and, more particularly, to a car wash dolly design that uses a single, solid shaft with two camshaft lobes and a series of snap ring grooves.
2. Brief Description of Related Art
Certain auto-laundry systems, otherwise popularly known as “car washes,” use endless chain conveyors of the type having “dollies” linked into the continuous-loop chain of a conveyor at regular intervals. These dollies are used to push vehicles along a track by engaging the tread surface of the tires of the vehicle. The dollies, in turn, are connected into the continuous loop chain by means of a center link.
The track structure which is used in combination with the chain and the dollies typically comprises three separate tracks mounted in parallel and at different levels. The top track accommodates the tire of the vehicle being washed and also provides the travel path for dollies which are selected at any given time to push the vehicle along the track. An intermediate level track provides the forward track for unselected dollies to continue to move on, and the bottom level track provides a return path for the dollies. A selector is used to transfer dollies from the intermediate to the top level tracks when a vehicle is present to be conveyed.
The U.S. Pat. No. 7,243,605 to Belanger et al. describes a car wash dolly design that utilizes a steel axle member in the form of a steel bolt having a threaded end which receives a nut. A center link is mounted on the axle member and three different pairs of wheels are mounted on the axle member on opposite sides of the center link. Bearings are provided between all of the wheels for independent rotation of the wheels.
A dolly employing such a bolt-based design includes many lose parts that are “assembled” via the bolt which holds bushing tubes for each wheel, wheels, and the center link in place to produce the final structure. In other words, a single, thin bolt is forced to carry many components and hold them in place while bearing the weight of a vehicle. This arrangement frequently leads to bending of the bolt during operation, thereby necessitating removal and replacement of the damaged dollies. Furthermore, the bolt and nut engagement may become lose under certain operational conditions. Hence, the bolt-based dolly design may be commercially undesirable because it leads to a reduced lifespan of the dolly, resulting in expensive repairs/replacements.